1. Field of the Invention
The present invention relates generally to a mounting structure for a continuity testing unit. More specifically, the present invention is directed to a mounting structure for a continuity testing unit in which a plurality of continuity testing units used to perform a continuity test for respective connectors of a wire harness are arranged in a matrix on a test board.
2. Description of the Related Art
A conventional mounting structure for a continuity testing unit is disclosed in Japanese Patent Application Publication No. 2007-85926 and is shown in FIG. 10. This conventional mounting structure for a continuity testing unit includes a test board 61 having a plurality of rails 63 arranged parallel to each other. A plurality of continuity testing units 62 used to test an electrical continuity of a connector of a wire harness is mounted to the rail 63 via a pin (not shown). The rail 63 is provided with a groove arranged along a lengthwise direction of the rail 63. The pin includes a tip portion arranged to open outward to engage with the groove of the rail 63.
The continuity testing unit 62 includes a plate portion indicated by the sign 62, a connector mounting part (not shown) communicated with a connector insertion aperture 64 formed on the plate portion 62, a testing part having a probe pin arranged to move up into and down out of the connector mounting part and an air cylinder arranged to move the testing part up and down. In FIG. 10, there is also shown a dummy plate 65 having no connector insertion aperture 64.
In operation, the respective connectors of the wire harness is inserted into the respective connector insertion apertures 64 downwardly by a worker. Then a test-start button is pushed by the worker to move the probe pin upward to so that the probe pin is placed in contact with a terminal of an electric wire within the connector. Thus, the probe pin, an electric wire connected to the probe pin, the terminal and the electric wire connected to the terminal together form a closed circuit, so the electrical continuity is detected.
Another example of a conventional mounting structure for a continuity testing unit is disclosed in Japanese Patent No. 3446675 in which a continuity test board includes a plurality of connector insertion apertures, and a continuity testing unit is mounted under or inside the connector insertion aperture. The continuity test board also includes a control part and a test-result indication part.
However, the above-described conventional mounting structure for a continuity testing unit uses the intricately-shaped pin having the tip portion arranged to open after being inserted into the groove of the rail 63. Thus, the use of such intricately-shaped pin causes an increase in cost. Although it is possible to use a bolt and a threaded hole instead of the above-described pin and the groove, it requires more time to attach or remove the bolt and it also requires a separate fixation tool. In addition, although the pin can be fixed to anywhere in the groove of the rail 63, it is difficult to restore the exact mounting position of the continuity testing unit 62.